Electrical contact

ABSTRACT

An electrical contact, formed in a one-piece metallic construction and having spaced fingers joined thereto in inclined relation that define locking elements for the contact when it is inserted in a bore of a contact block.

United States Patent l 1 1 3,587,036

[72] Inventor Donald G. McGregor [56] References Cited I N 532% UNITEDSTATES PATENTS P 2,961,634 11/1960 Elliott et a1. 339/276 [22] FiledNov. 3, I969 [45] Patented Jam 22 1971 3,059,214 10/1962 Heller 339/184(73] Assignee Electrix Corporation O IG PATENTS Esmond, RJ. 1,238,6707/1960 France 339/217 (S) 474,525 11/1937 Great Britain 339/217 (S)Primary ExaminerJames A. Leppink [5 ASH-SIG!!! Examiner-Robert Hafer 4claims, 5 naming at Attorney-Salter and'Michaelson 339/223 ABSTRACT: Anelectrical contact, formed in a one-piece [51 1 Int. Cl..- HOlr 9/08metallic construction and having spaced fingers joined thereto (50]Field of Search....' 339/217, in inclined relation that define lockingelements for the con- 223, 48, 49 tact when it is inserted in a bore ofa contact block.

2a 12 VA? 30 PATENTEnJuuzzlsn 3,587,036

I nventon ,Donald GZMGreyor,

ELECTRICAL CONTACT BACKGROUND OF THE INVENTION The present invention hasparticular application as a contact button for use in an insulatedcontact block that may be formed as part of an electric socket, anelectrical fixture, light assembly or other electrical device.

Electrical contact buttons of the type embodied in the present inventionhave been in use heretofore in lighting fixture assemblies and otherkinds of assemblies that require a contact button to be secured to theend of a conductor lead. Heretofore, the contacts were secured in acontact block, a bore being provided in the block for receiving thecontact therein. Since there was no provision heretofore for securingthe contact button within the insulated block, the contact oftentimesworked loose, and relative movement then occurred between the contactand the block in which it was mounted. This, of course, created problemsin the operation of the device in which the contact was located, andeventually caused the device to become inoperative.

SUMMARY OF THE INVENTION The present invention includes an electricalcontact for insertion into a bore formed in an insulated contact block,the contact comprising a one-piece metallic body portion having a headmember and a shank portion joined to the head member. Lugs are formed aspart of the shank portion for securing a conductor lead to the contact;and in order to retain the contact in fixed position within thecontactblock in which it is inserted, spaced fingers are joined to theshank portion and are inclined outwardly in a direction toward the headportion. The inclined fingers define locking elements for the contactwhen the shank portion is inserted in the bore of the insulated contactblock, the inclination of the fingers permitting the shank portion to beinserted into the bore but preventing withdrawal therefrom.

Accordingly, it is an object of the invention to provide an electricalcontact that is formed in a one-piece construction and that includeslocking fingers that prevent withdrawal of the contact from a contactblock in which it is inserted.

Other objects, features and advantages of the invention will becomeapparent as the description thereof proceeds when considered inconnection with the accompanying illustrative drawings.

DESCRIPTION OF THE DRAWING In the drawing which illustrates the bestmode presently contemplated for carrying out the present invention:

FIG. 1 is a top plan view of the contact embodied in the presentinvention;

FIG. 2 is a side elevational view of the contact;

F IG. 3 is a sectional view taken along line 3-3 in F IG. 1;

FIG. 4 is a bottom plan view of the contact; and

FIG. 5 is a sectional view of a contact block showing the contactembodied in the present invention locked therein.

DESCRIPTION OF THE INVENTION Referring now to the drawing, the contactembodied in the present invention is generally indicated at and,although shown in finished form in the various figures, the contact isfabricated of a blank of sheet metal and then formed in theconfiguration illustrated.

The contact I0 includes a shank portion generally indicated at 12 thatis defined by a bottom wall 14 to which sidewalls l6 and 18 areintegrally joined. Joined to the bottom wall 14 is a reduced section 20to which a head portion generally indicated at 22 is integrallyconnected. As seen in FIGS. 2 and 3, the sidewalls l6 and 18 of theshank portion 12 in the initial fabrication thereof are turned upwardlyat substantially right angles with respect to the bottom wall 14 and arecut out intermediate the ends thereof to define spacedlugs 24, 26 and28,

30. The lugs 24 and 28 cooperate as will be described to receive aninsulated portion of a conductor lead therebetween, while the lugs 26and 30 are adapted to be folded into engaging relation with the exposedwire portion of the conductor lead.

Formed as part of the sidewalls l6 and I8 and located adjacent to thelugs 26 and 30 are fingers 32 and 34. As shown in FIG. 1, the fingers 32and 34 are inclined outwardly with respect to the head portion 22 andare disposed at substantially a 45 angle with respect to thelongitudinal axis of the shank portion 12. As will be described, thefingers 32 and 34 define locking elements that provide for locking ofthe contact 10 within a bore of a contact block. Since it is desirablethat the fingers 32 and 34 make a point contact engagement with thesidewalls of the bore in which the contact 10 is inserted, the lateraldimension of the fingers is substantially reduced with respect to thelongitudinal dimension of the lugs 24, 28 and 26, 30. This relationshipis illustrated in FIG. 2 wherein the lateral dimension of the fingersrepresented at l is considerably less than the height indicated at h ofthe lugs.

The head portion 22 of the contact 10, which is formed as an integralpart of the contact construction and defines an extension of the shankportion 12, includes a convex button 36 joined to the reduced extensionby an inclined portion 38. A reversely turned portion 40 is joined tothe button 36 and has an elongated extension 42 joined thereto thatoverlies the reduced section 20 and the bottom wall 14 of the shankportion 12. As will be described, the extension 42 is relatively longand extends substantially the length of the channel defined by theopposed walls 16 and 18. The conductor lead that is received in thechannel is locked into engagement with the extension 42 and thus acts topositively retain the button 36 in the position thereof for makingelectrical engagement with a complementary contact.

A conductor cable or lead generally indicated at 44 in FIG. 4 isattached to the contact 10 by locating a sheath portion 46 thereofbetween the lugs 24 and 28 and then locating the stripped cable 47between the lugs 26, 30 and in overlying relation on the extension 42.The lugs 24 and 28 are then folded into clamping relation over thesheath 46, and the lugs 26, 30 are similarly folded into clampingengagement with the exposed cable 47, whereby the conductor cable 44 isfirmly secured to the contact 10.

In use of the contact 10 as contemplated by the present invention, thecontact is normally inserted into a contact block such as represented at48 in FIG. 5. Formed in the contact block 48, which is preferably moldedof an insulating plastic material, is a bore 50. A countersunk portion52 is formed in the contact block 48 for receiving the contact button22, the countersunk portion 52 communicating with a reduced bore 54 thatdefines a shoulder 56 with the bore 50. The diameter of the reduced bore54 is somewhat less than the diameter of the contact button 22, and thusthe button 22 is received within the countersunk portion 52 but isprevented from being withdrawn into the bore 54.

The contact 10, together with the conductor cable 44, is threaded intothe bore 50 in the block 48, the inclination of the fingers 32 and 34being such that they will engage the sidewalls of the bore 50 when thecontact is fully inserted into the block 48. Since the fingers 32 and 34have a spring action because of the metallic material from which thecontact 10 is formed, they will permit insertion of the contact throughthe reduced bore 54. When the fingers 32 and 34 clear the shoulder 56,they snap thereunder into engagement with the walls of the bore 50 andwill prevent withdrawal of the contact 10 outwardly of the contact block48. Since the button 22 blocks the contact against inward movement ofthe block 48 and the fingers 32 and 34 prevent outward movement of thecontact, it is seen that the contact is firmly secured within thecontact block 48. Movement of the contact 10 with respect to the block48 is thus prevented, and the contact button 22 is firmly fixed inposition and will be available for positive electrical engagement with acomplementary contact that is moved into engagement therewith.

What I claim is:

1. An electrical contact for insertion into a bore formed in aninsulated contact block, comprising a one-piece metallic body portionhaving a head member formed with a convex portion that is engageable byan external contact member for establishing electrical communicationtherewith, a shank portion joined to said head member and extendinginwardly thereof, a reduced extension joined to said head member andextending reversely with respect thereto for location in overlyingrelation on said shank portion, said reduced extension and the portionof said shank portion over which said extension lies defining anelongated neck section, opposed and spaced lugs joined to said shankportion and being foldable for capturing a wire conductor of anelectrical lead therebetween, and a pair of spaced fingers integrallyjoined to said shank portion adjacent to said lugs and being inclinedoutwardly in a direction toward said head portion, the longitudinaldimension of said fingers being somewhat less than that of saidelongated neck section, wherein the outermost ends of said fingers aresubstantially spaced from said head member said inclined fingersdefining locking elements for said contact when the shank portionthereof is inserted in the bore of said insulated contact block, theinclination of the fingers permitting the shank portion to be insertedinto said bore, but preventing withdrawal therefrom by engaging thesidewalls thereof.

2. An electrical contact as set forth in claim 1, said lugs beinginitially formed substantially at right angles to said extension and theportion of the shank portion on which said extension overlies, and thelateral dimension of the fingers being substantially less than thelongitudinal dimension of said lugs.

3. An electrical contact as set forth in claim 2, said fingers beinginclined with respect to the longitudinal axis of said shank portion atan angle of substantially 45.

4. An electrical contact as set forth in claim 1, said extension havinga longitudinal dimension that is sufficient for locating the wireconductor in overlying relation therewith when the lugs are folded overthe wire conductor.

1. An electrical contact for insertion into a bore formed in aninsulated contact block, comprising a one-piece metallic body portionhaving a head member formed with a convex portion that is engageable byan external contact member for establishing electrical communicationtherewith, a shank portion joined to said head member and extendinginwardly thereof, a reduced extension joined to said head member andextending reversely with respect thereto for location in overlyingrelation on said shank portion, said reduced extension and the portionof said shank portion over which said extension lies defining anelongated neck section, opposed and spaced lugs joined to said shankportion and being foldable for capturing a wire conductor of anelectrical lead therebetween, and a pair of spaced fingers integrallyjoined to said shank portion adjacent to said lugs and being inclinedoutwardly in a direction toward said head portion, the longitudinaldimension of said fingers being somewhat less than that of saidelongated neck section, wherein the outermost ends of said fingers aresubstantially spaced from said head member said inclined fingersdefining locking elements for said contact when the shank portionthereof is inserted in the bore of said insulated contact block, theinclination of the fingers permitting the shank portion to be insertedinto said bore, but preventing withdrawal therefrom by engaging thesidewalls thereof.
 2. An electrical contact as set forth in claim 1,said lugs being initially formed substantially at right angles to saidextension and the portion of the shank portion on which said extensionoverlies, and the lateral dimension of the fingers being substantiallyless than the longitudinal dimension of said lugs.
 3. An electricalcontact as set forth in claim 2, said fingers being inclined withrespect to the longitudinal axis of said shank portion at an angle ofsubstantially 45*.
 4. An electrical contact as set forth in claim 1,said extension having a longitudinal dimension that is sufficient forlocating the wire conductor in overlying relation therewith when thelugs are folded over the wire conductor.